The present invention relates to a monitoring system for monitoring wearers of respiratory equipment, and to a mobile part and to a base station for use in such a system.
Fire departments employ respiratory equipment, so-called compressed-air breathing apparatuses, which are independent of ambient air conditions. Such apparatuses enable fire fighters to still carry on their work in rooms which are completely smoke-filled. The breathing air required for this is carried on the back in one or two steel or composite-material cylinders. The operating pressure of such cylinders is 200 or 300 bar depending on type, with a cylinder capacity of 4 and 6 liters, respectively, of compressed air. Use is made, for example, of a Drxc3xa4ger PA94+ compressed-air breathing apparatus with two 4-liter, 200 bar steel cylinders. In this case, the air supply is 1600 liters, which is sufficient for a mission, or use, duration of approx. 20 minutes in the case of medium-heavy work. Normally, the mission time of the personnel, who act exclusively as a team, is monitored by a fireman who makes a note of the starting time of the mission. If, after a certain length of time, there has been no communication from a team, then action can be taken and rescue measures initiated. However, such a manual procedure involves some inherent risks, because the monitoring fireman must calculate for all personnel the remaining mission time, which may vary because of different starting times. Furthermore, it is difficult to locate a fireman who is in distress if he is unable to trigger an alarm.
The German Patent Document No. DE 197 42 758 describes a monitoring device for monitoring persons carrying out time-limited activities. The monitoring device has a time-measuring device which can be triggered by the very person who is to be monitored. An alarm apparatus implemented in the monitoring device is activated when a preset time has elapsed since the triggering of the time-measuring device,
A similar microprocessor-controlled monitoring system for time-limited activities is known from German Patent Document No. DE 296 20 650 which, in addition, features a display for the visualization of all parameters.
It may be that the safety of persons to be monitored can be increased through the use of such monitoring devices as compared with a purely manually active monitoring person. However, there is the disadvantage that the persons to be monitored are themselves not in communication with the monitoring device and, in addition, cannot be promptly informed about the instantaneous time lapse.
European Patent Document No. 08 01 368 A1 describes a monitoring device which can be used in conjunction with respiratory equipment worn, for example, by fire fighters. In addition to a pressure sensor, this device also contains a motion sensor. An alarm apparatus generates a warning signal when the pressure reaches a critical value, or when no movement of the user is detected any longer. Furthermore, the monitoring device has means for transmitting data from the pressure sensor and the motion sensor, as well as alarm signals, via an infrared connection to an external radio device, which in turn routes the data via a radio link to a manager monitoring the user.
U.S. Pat. No. 5,392,771 discloses a monitoring system for portable respiratory equipment. The monitoring system has a transmitter and a receiver separate therefrom. Both the transmitter and the receiver are carried by the user of the respiratory equipment. The transmitter is allocated, for example, to a pressure sensor and transmits the detected data, for instance, via radio to the receiver. In contrast to the known monitoring system, in which a radio transmission takes place between a transmitter and a receiver which are arranged in the immediate vicinity of the user, the present invention relates to a radio transmission between a mobile device carried by the user and a base station arranged at a distance from the user.
Consequently, an object of the present invention is to provide a monitoring system, a mobile part and a base station with which it is possible to monitor and protect wearers of respiratory equipment better than before during a mission and, in particular, in an emergency.
An object of the present invention is to create an essentially automatically operating monitoring system which is capable, at each instant of a mission, of informing each team member wearing respiratory equipment and the monitoring person responsible for that team about the condition of his/her respiratory equipment or of all respiratory equipment and which is capable, in an emergency, of triggering an alarm both in the case of the respiratory-equipment wearer who is in distress and in the case of the monitoring person.
The monitoring system has at least one mobile part which is connectable to a compressed-air breathing apparatus that can be fastened, for example, on the back of a wearer. The mobile part is allocated at least one sensor for acquiring predetermined status data, particularly status data of the compressed-air breathing apparatus. Also provided is a base station capable of communicating with the mobile part of each respiratory-equipment wearer via a wireless connection. The base station is advantageously in the form of a mobile apparatus which can be taken to any location by the monitoring person. In order to be able to transmit to the base station the status data which have been acquired by the sensor, the mobile part has a radio transmitting apparatus. Similarly, the base station contains a radio receiving apparatus for receiving the status data transmitted from the mobile part. Both the mobile part and the base station contain a warning and/or alarm apparatus which generates visual and/or audible signals as a function of the acquired status data. The warning and/or alarm apparatus may, for example, be a loudspeaker and light-emitting diodes which can be suitably driven.
To enable those respiratory-equipment wearers currently on mission to be monitored in the base station, provision is made in the mobile part for a central control unit to transmit to the base station a message for logging the respective mobile part on or off at the base station.
To achieve a high degree of safety in the monitoring of the wearers of respiratory equipment, it is possible to connect to the mobile part: a pressure sensor for measuring the pressure of the compressed-air cylinders of the compressed-air breathing apparatus, a temperature sensor for measuring the ambient temperature of the respiratory-equipment wearer, a motion sensor for detecting motions of the respiratory-equipment wearer and/or a sensor for detecting an emergency-call function triggered by the respiratory-equipment wearer. Such an emergency-call function can be triggered, for example, by pulling a handle attached to the carrying strap of the compressed-air breathing apparatus.
The warning and/or alarm apparatus is activated as soon as the respective sensors have detected that a preset threshold value has been undershot or exceeded.
Further provided is an adjustable time-measuring apparatus for measuring the time elapsed since the triggering of the time-measuring apparatus. As a function of the pressure of the compressed-air cylinder, it is also possible, with the aid of the time-measuring apparatus and a central control unit, to calculate the remaining mission time of the respective respiratory-equipment wearer and to communicate this to the wearer of the respiratory equipment.
The central control unit is connected to each sensor, the time-measuring apparatus and the warning and/or alarm apparatus, and assumes the control and monitoring of the mobile part.
Normally, the quantity of air remaining in the compressed-air breathing apparatus is checked by measuring the pressure in the compressed-air cylinder using a pressure gauge, it being necessary for the respiratory-equipment wearer to take a reading of the pressure on the pressure gauge at regular intervals. To save the wearer from having to read off such system data, a speech output apparatus is provided which, in response to the measured status data, is capable of transmitting predetermined messages, particularly the pressure, the temperature as well as warning and alarm messages, in speech form at predetermined time intervals to the wearer of the respiratory equipment.
For this purpose, the mobile part expediently features an interface for the wire-bound and wireless connection of an earpiece or headphone, implemented in the helmet of the respiratory-equipment wearer, to the speech output apparatus.
To be able to monitor the conditions of all logged-on wearers of respiratory equipment at a glance, the base station is provided with a display device capable of displaying the status data of all logged-on mobile parts.
To be able to evaluate and process the acquired status data externally as well, the mobile part is provided with a memory for the temporary storage of the acquired status data and with an interface for the connection of an external computer to which the stored status data can be output.
To enable the measured status data to be transmitted reliably to the base station via a radio channel, first of all, each sensor is allocated an analog/digital converter which converts the analog measured quantities into digital data. Next, the digitized status data are supplied to an encoder which converts the digital status data to be transmitted, for example, into a frequency-doubled bi-phase M format. The base station is provided with a correspondingly designed decoder for decoding the received encoded status data.
The power is supplied to the mobile part and the base station, for example, by NiCd batteries which can be fastened on the back of the respective device by velcro tape.
To prevent the speech output apparatus from being activated unnecessarily often, thereby increasing the power consumption of the mobile part, the control unit is designed in such a way that it compares the instantaneous pressure with the last-measured pressure of the compressed-air cylinder of the compressed-air breathing apparatus and activates the speech output apparatus only if the pressure difference has exceeded a predetermined value.
The present invention also provides a mobile monitoring device is provided for attachment to a compressed-air breathing apparatus of a monitoring system. The mobile monitoring device has a central control apparatus which is connectible to at least one sensor for measuring predetermined status data, particularly status data of a compressed-air breathing apparatus. Further provided is a radio transmitting apparatus for the wireless transmission of the measured status data to a base station; additionally provided is a warning and/or alarm apparatus which generates visual and/or audible signals as a function of the measured status data.
The central control unit is designed for transmitting a message for logging the mobile part on or off at the base station.
In an embodiment of a device according to the present invention, the mobile monitoring device includes a control apparatus to which can be connected a pressure sensor, a temperature sensor, a motion sensor, a sensor for detecting an emergency-call function triggered by the respiratory-equipment wearer and/or an adjustable time-measuring apparatus.
Further provided in the mobile transmission device is an interface for the wire-bound or wireless connection of a headphone to the speech output apparatus, as well as an interface for the connection of an external computer.
The present invention also provides a base station for use in a monitoring system. For this purpose, the base station has a radio receiving apparatus for receiving the status data transmitted from a mobile part attached to a compressed-air breathing apparatus; a warning and/or alarm apparatus which generates visual and/or audible signals as a function of the received status data; and a display device for displaying the status data of each mobile part logged onto the base station.
Using the present invention, vital data from a plurality of respiratory-equipment wearers as well as system status data can be transmitted via a radio connection to a base station and, depending thereon, alarm messages can be triggered both in the case of the monitoring person and in the case of the respiratory-equipment wearers. In this context, it is advantageous that rescue measures can be initiated very much earlier and that human error is largely eliminated, since the data are continuously exchanged.